<h2>Abstract</h2><h3>Background</h3> Coronary obstruction during transcatheter aortic valve replacement (TAVR) is a rare, yet life-threatening, complication. The routine use of left main (LM) protection with or without stent placement in high-risk patients remains controversial. The aim of this study was to evaluate the outcomes of LM protection during TAVR and identify anatomic factors associated with need for stent placement. <h3>Methods</h3> We retrospectively reviewed all TAVR cases (native and valve-in-valve) performed in our institution between 2014 and 2019 and identified patients who underwent LM protection with a coronary wire, balloon, and/or stent during the procedure. We compared the pre-TAVR computed tomography aortic root characteristics, procedural data, short-, and long-term outcomes among the patients who eventually received an LM stent and those who did not. <h3>Results</h3> Among 1925 TAVR patients, 41 (2.1%) underwent LM protection, and 10 of them (25%) had eventually a stent placed in the LM for threatened obstruction after valve deployment. In the native TAVR group (<i>n</i> = 35), 8 patients underwent LM stenting. A larger TAVR prosthesis, larger annular circumference (83.8 vs 76.1 mm; <i>P</i> = .038), lower ratio of sinotubular junction diameter to prosthesis size (1.02 vs 1.11; <i>P</i> = .032), and longer left coronary cusp (15.1 vs 13.9 mm; <i>P</i> = .18) were associated with higher incidence of LM stenting. In the valve-in-valve TAVR group (<i>n</i> = 6), 5 patients had a valve-to-coronary distance of less than 4 mm, and 2 of them received an LM stent. Both stent and nonstent groups had excellent outcomes with no major adverse cardiovascular events or coronary obstruction at 30 days. After a median follow-up of 351 days, 4 patients died (9.7%) (1 in the stent and 3 in the nonstent group), without any cases of late coronary obstruction or percutaneous coronary intervention in either group. <h3>Conclusions</h3> LM protection with a coronary guidewire, balloon, or stent is a safe and effective method of coronary protection during TAVR in appropriately selected high-risk patients. Annular circumference, prosthesis size, left coronary cusp length, LM ostial height, and ratio of sinotubular junction to prosthesis size are important predictors of stent deployment.